From 428f3570f98224e7fd2ff18e1e199068b3285a5d Mon Sep 17 00:00:00 2001
From: Stef Walter <stef@memberwebs.com>
Date: Sat, 21 Jan 2006 19:18:33 +0000
Subject: Build a slightly better polling RRD collector.

---
 tools/rrdui-collect.py | 106 ++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 83 insertions(+), 23 deletions(-)

diff --git a/tools/rrdui-collect.py b/tools/rrdui-collect.py
index 892fdf8..0585812 100644
--- a/tools/rrdui-collect.py
+++ b/tools/rrdui-collect.py
@@ -1,13 +1,27 @@
 #!/usr/bin/python
 
-import os, sys, time
+import os, sys, time, math
 import rrdtool
 
 from rrdui import *
 
-def readItemValue(host, community, oid):
+# This entire module is nasty. Don't do this at home. It's a python interim
+# replacement for a C daemon that needs writing. It's about the least efficient
+# way to go about SNMP polling.
 
-    cmd = "snmpget -c %s -Ov -OQ -v 2c %s %s" % (community, host, oid)
+class Timer:
+    def __init__(self, interval, cmds, item):
+        self.interval = interval
+        self.cmds = cmds
+        self.item = item
+        self.last = 0
+
+def logMsg(msg):
+    stamp = time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(time.time()))
+    print >> sys.stderr, "%s: %s" % (stamp, msg)
+
+
+def readItemValue(cmd):
     p = os.popen(cmd, "r")
     out = p.read()
     (pid, status) = os.wait()
@@ -19,41 +33,87 @@ def readItemValue(host, community, oid):
         pass
 
     if status != 0:
-        print "Couldn't query %s for %s" % (host, oid) # XXXXXX
+        logMsg("WARNING: Couldn't query %s for %s" % (host, oid))
         out = "U"
-
     return out.strip()
 
 
-def updateItems(graphs):
-    for item in graphs:
-        if not os.path.exists(item.filedata):
-            continue
+def loadTimers(items):
+    timers = []
 
+    for item in items:
         (fields, interval) = item.getPollingInfo()
 
-        values = {}
+        if not len(fields):
+            continue
+
+        if interval < 10:
+            logMsg("WARNING: Ignoring interval less than 10 seconds")
+            interval = 10
+
+        cmds = {}
         for fieldname in fields.keys():
-            info = fields[fieldname].split(":")
+            field = fields[fieldname]
+            info = field.split("/")
             if len(info) != 4:
-                raise "Bad src format" # XXXXXXXXX
+                logMsg("ERROR: Bad src format: %s" % field)
+                sys.exit(1)
             if info[0] != "SNMP":
-                raise "Unknown src method: %s" % info[0] # XXXXXXXXX
+                logMsg("ERROR: Unknown src method: %s" % info[0])
+                sys.exit(1)
+
+            # TODO: Note that we don't check our arguments ...
+            # Nasty and temporary untill we get the C daemon going
+            cmd = "snmpget -c %s -Ov -OQ -v 2c %s %s" % (info[2], info[1], info[3])
+            cmds[fieldname] = cmd
+
+        timer = Timer(interval, cmds, item)
+        timers.append(timer)
 
-            value = readItemValue(host = info[1], community = info[2], oid = info[3])
-            values[fieldname] = value
+    return timers
 
-        print ":".join(values.keys()), ":".join(values.values())
-        args = [item.filedata, "--template", ":".join(values.keys()),
-                "N:%s" % ":".join(values.values())]
+def updateItem(timer):
+
+    if not os.path.exists(timer.item.filedata):
+        logMsg("WARNING: RRD file does not exist: %s" % timer.item.filedata)
+        return
+
+    values = {}
+    for field in timer.cmds.keys():
+        values[field] = readItemValue(timer.cmds[field])
+
+    args = [timer.item.filedata, "--template", ":".join(values.keys()),
+            "N:%s" % ":".join(values.values())]
+    try:
         rrdtool.update(*args)
+        print args
+    except Error, e:
+        logMsg("ERROR: Couldn't update RRD file: %s (args: %s)", e.value, args)
 
 
-graphs = loadGraphs()
-while True:
-    updateItems(graphs)
-    # TODO: Work out the interval stuff. for now all at 10 seconds
-    time.sleep(10)
 
+graphs = loadGraphs()
+timers = loadTimers(graphs)
 
+while True:
 
+    # Update when and where necessary. Note we keep calling
+    # time.time() as updating takes time
+    for timer in timers:
+        if (timer.last + timer.interval) < time.time():
+            updateItem(timer)
+            timer.last = time.time()
+
+    # Now figure out how long to sleep
+    next = 0
+    for timer in timers:
+        if not timer.last:
+            continue
+        if not next or (timer.last + timer.interval) < next:
+            next = timer.last + timer.interval
+
+    secs = next - time.time()
+    print "%d %d %d" % (secs, next, time.time())
+    if(secs > 0):
+        print "sleeping for %d" % secs
+        time.sleep(secs)
-- 
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